AU2017273194B2 - Method and arrangement for monitoring specific activity parameters of the human heart - Google Patents

Abstract

The subject of invention on one hand is a method for monitoring specific activity parameters of the human heart, where ECG and PCG signal monitoring is performed simultaneously by at least two sensors placed on the chest, in such a way that the ECG signal is utilized as an anchor, that is, a reference time point during PCG monitoring, and monitoring is performed with a measuring unit (M) consisting of a couple of measuring heads (1, 2) containing combined ECG and PCG sensors, a controlling master measuring head and a slave measuring head performing synchronized implementation, and a computing evaluating unit (K) which is in wireless data communication connection with the above unit and is capable of data processing. The subject of invention on the other hand is a measuring arrangement for monitoring specific activity parameters of the human body consisting of a measuring unit (M) and an evaluating unit (K) having a wireless communication connection with the measuring unit. The measuring unit (M) contains two measuring heads (1, 2) designed as master and slave measuring heads (1, 2). Each measuring heads (1, 2) contain PCG and ECG sensors which are necessary for the simultaneous examination of the hearts electromechanic activity; the master measuring head (1) contains the communication stage providing wireless communication contact with the evaluating unit (K).

Description

Method and measuring arrangement for monitoring specific activity parameters of the human heart

The subject of the claimed invention is a method of monitoring specific activity parameters of the human

heart according to claim 1, along with an equipment for the implementation of the method according to claim

7. In addition, the invention concerns computer program products as well in order to implement the

recommended method.

Auscultation of the heart has a centuries-long history. The stethoscope, Laennec's epoch-making invention

was an important milestone in 1816 as it was the first medical device. Since then the modern medical

technology has provided several new options for the examination of the heart (e.g. by ultrasound imaging),

nevertheless, inexpensive and widely available technologies based on auscultation have remained valuable

tools in primary examinations, especially on the level of primary care.

The membrane sensor with the attached rubber tubing channels the sounds and finally the doctor gets the

auscultation experience by direct vibration of the tympanic membrane via the eartip - it is still used widely. Its

drawback is that the evaluation is subjective and it is difficult to teach.

The top products of the cutting-edge commercial solutions are digital stethoscopes which were launched a

few years ago. These convert the vibration of the thoracic wall evoked by heart activity to electronic signals

which allows the performance of optional signal processing steps, signal amplification, filtering, measurement

of its parameters, visualization, forwarding, electronic storage, etc. The advances made in the last few decades

are well characterized by the study of Yashaswini and Satyanarayana: "The design of an electronic Stethoscope

- Review" published in International Conference on Computer Science and Informatics, 2012, Hyderabad issue,

pp. 37-41. A more recent and detailed review is given in the article of Leng et al. BioMed Eng OnLine (2015)

14:66 DOI 10.1186/s12938-015-0056-y.

The type 3200 digital stethoscope of Littmann measures the vibrations of only one auscultation site at a time in

accordance with the traditions, and at the same time, it tries to deprive the registered signals from the

disturbing effect of the signal sources outside of the heart by filtering and the suppression of environmental

noise. In order to prevent the subjective elements of expertise to limit correct diagnosis, it allows distance

diagnostic consultation of the heart's acoustic signals - through networks with appropriate safety - between the

physicians of optional geographic locations/institutes.

Although the Thinklabs One device (Thinklabs Electronic Stethoscope, Icomnj)

measures the vibrations of only one auscultation site by its novel capacitive sensor, the control elements

placed on the measuring head allow the adjustment of the transfer band and amplification during

measurement. The measured signals are stored on an external storage device following digital conversion, and

an earphone may be attached for the physician during the examination. The smartphone or computer (PC) can

display, store and/or forward the vibrations in time and time frequency range via Bluetooth connection.

The CardioSleeve device of Rijuven (http://www.rijuven.commrnedicaldevices/cardiosleeve) is a supplementary

unit which can be attached to any traditional stethoscope, allowing the use of older devices in the modern

digital world. It stands out by the supposedly important innovation that via its dry ECG electrodes, the proprietary supplementary unit is able to record some of the ECG channels similar to Einthoven I, II or III leads along with the heart sound signals, allowing the correlation of the timing and duration of the sounds to the electronic (depolarization and repolarization) cycle leading to heart contraction and release. However, the above mentioned three leads cannot be recorded simultaneously, but in three steps, by the rotation of the measuring head. As a further note, it has to be mentioned that the ECG electrodes of Rijuven's device fall outside of the standard points of measurement. Nevertheless, this solution allows the identification of the location, duration, and envelope of the sounds and murmurs in relation with the ECG signals that give a quantitative image of the electrical activity, and also allows the detection of arrhythmic or extra beats.

We found that at the level of known and commercially available devices, there is still no solution for the

reliable and useful distinction of heart sounds and murmurs developing as a consequence of structural errors

(such as not proper valve closure or opening). As regards research, e.g., the study of Akbari et al.: ,,Digital

Subtraction Phonocardiography (DSP) applied to the detection and characterization of heart murmurs"

, Biomed Eng Online. 2011 Dec 20;10:109. doi: 10.1186/1475-925X-10-109 made a recommendation on a

method of distinguishing heart murmurs from heart sounds, but as far as we know it was not utilized

industrially. The proposed solution exploits the fact that heart sounds are repeated causally in each cycle, while

murmurs are random due to the turbulent blood flow. In such cases, if the beginning of QRS wave (i.e.

ventricular repolarization) is known in each cycle, after the subtraction of the heart sound signals in the

consecutive cycles, the difference will show the murmurs' time function, and the heart sounds' time function

will disappear during the creation of difference. The limitation of the method is that it does not define the

beginning of the sounds, although it is an essential deficiency in terms of determining some of the often-used

clinical parameters of heart activity, such as pre-ejection period (PEP) or left ventricular ejection time (LVET).

In summary, commercial stethoscopes are not suitable for the detailed examination of the four heart valves in

relation to the guiding ECG signal, that is, they are not able to accurately examine the opening and closure of

the atrioventricular and ventriculo-aortic valves, that is, the valves of the right and left heart, to detect

structural errors, and in pathological cases, the highly precise determination of the beginning and end of heart

sounds and murmurs. As a result, the parameters used by clinicians for the assessment of the heart's

mechanical and electromechanical activity are inaccurate.

Our invention is based on the notion that we can reliably determine the heart sound parameters, their relative

timing and the additional cardiac murmurs that occur in case of imperfect heart function, with a reproducible

result, if the mechanical vibrations of the body surface (PCG) and bioelectronic (ECG) signals initiating the

mechanical activity are measured simultaneously, with more than one measuring head at the auscultation

sites of the body surface, and it can be used as an anchor (reference) for error-free evaluation.

The set goal was achieved according to the method of claim 1 on the one hand, and by using a measuring

arrangement according to the features of claim 7 on the other hand. The main advantageous implementation

versions of the method are listed under the dependent claims.

The invention is further presented in detail on the basis of an exemplary implementation and the introduction

of a measuring arrangement with reference to the accompanying drawings as follows:

Fig. 1 shows the basic draft of the measuring arrangement according to the invention;

Fig. 2 shows the exemplary measuring heads used in the measuring arrangement from below with the

cable connection and combined sensors between;

Fig. 3 shows the information appearing on the liquid-crystal display placed on the upper surface of the

"master" measuring head according to Fig. 2;

Fig. 4 shows the cardiac auscultation sites and also presents the ribs and sternum to facilitate

anatomical orientation;

Fig. 5 shows the block scheme of the exemplary electronic setting of the "master" and "slave"

measuring heads;

Fig. 6 shows the graphic view of the measurement parameters that were taken into consideration

during the method according to the invention; and

Fig. 7 shows the key steps of measurement performed with the measuring arrangement an evaluation.

As we mentioned earlier, the deficiency serving as the ground of our invention's development is the

uncertainty of taking measurement parameters necessary for drawing conclusion, and one of the most

important objective of the study is to eliminate such uncertainties. This could be reached by monitoring

appropriate waves and setting corner/anchor time points.

As it is shown in Fig. 1, the measuring arrangement according to the invention consists of two separated main

parts: a measuring unit (M) and an evaluating unit (K). The measuring unit (M) in the presented case consists of

two measuring heads (1, 2) and the evaluating unit (K) consists of a smartphone. The two units have wireless

connection, in this example via Bluetooth technology which is widespread and well-known in mobile

communication. Of the two measuring heads (1, 2) comprising the measuring unit (M), measuring head 1 is the

so-called master head and measuring head 2 is the so-called slave head, and in this example there is a wire

connection between them. The presented measuring arrangement with the measuring head pair (1, 2)

combined with two sensors (PCG and ECG) and being in a master-slave relationship, the smartphone being in

wireless Bluetooth connection or other data-processing and archiving, that is, evaluating unit (K) with the

characteristics described in the methodological chapter leads to a solution which eliminates the substantial

deficiencies of the earlier solutions.

The measurement of the ECG and PCG signals takes place simultaneously in each cardiac cycle by measuring

heads 1 and 2 which together contain a bipolar ECG sensor and two heart sound (PCG) sensors (5, 6)

implemented by dry (or possibly gel-containing) electrodes (3, 4), see Fig. 5. The sensory electrode (3) of the

master (1) measuring head fulfils the function of the right leg electrode of the traditional 12-lead ECG, and

electrode 4 of measuring head 2 is not exploited in the presented example. Communication between measuring head 1 and 2 takes place via a flexible multiconductor cable (7). The role of the cable (7) apart from ensuring an electrical connection between measuring heads 1 and 2, is to enable the physician to wear the device hung on his/her neck between examinations, similarly to a conventional stethoscope. A display (8) is in place for monitoring the recorded signals during measurement which in the example is positioned on the top of the master (1) measuring head, recessed into its case. The detailed numerical and/or graphic result of the computerized signal processing and evaluation can be presented on the display of the smartphone comprising the evaluating unit (K). The combined setting of measuring heads 1 and 2 drafted here is a substantial element of the solution according to the invention.

The measuring heads 1 and 2 are not identical; measuring head 1 is more complex in terms of functionality,

and it is the "master" head within the set, ensuring synchronized operation with the "slave" measuring head,

along with the visual presentation of the ECG and PCG signals on the liquid-crystal display (8) during data

collection as shown as an example in Fig. 3.

Considering that the valves represent the operation of the left ventricle and right ventricle in pairs, it is logical

to simultaneously examine the physiologically "cohesive" two left ventricular and two right ventricular valves at

the auscultation sites 9 through 12 (see Fig. 4) where the cardiac auscultation sites (9-12) are shown, and the

ribs and sternum are also presented to facilitate anatomical orientation.

Further combinations allow the measurement of temporal and morphological differences between PCG

components originating from the left and right side.

In order to ensure practical applicability, the invention is the development of a measuring head combination (1,

2) suitable for use on both men and women is required, regardless of their size, anatomical composition, and

body posture. Due to the significant anatomical differences of the two sexes, the solution with two (1, 2)

measuring heads connected by a multiconductor cable (7) is recommended by all means for routine

examinations which allows the physician, relying on his or her knowledge of anatomy to place the sensors of

the measuring head set on the standard auscultation points without disturbing the patient. At the same time,

in order to preserve the traditions of device sporting, the physician can carry the measurement head set (1, 2)

according to the invention hung on his/her neck between examinations, similarly to a conventional

stethoscope.

Considering that the signals of the measuring heads (1, 2) are recorded digitally, the results of the data

collection can be evaluated by the physician acoustically as well as graphically in the form of time functions,

similarly to ECG and PCG records, depending on his/her preference. The latter takes place on the display (8)

built into the master (1) measuring head, see Fig. 3. The liquid-crystal display shown in Fig 3 provides

qualitative control option for checking the quality of the recorded signals during measurements and ensures

that the physician does not have to look at the display of the smartphone or any other device.

The final graphic and/or numerical result of the signal processing is presented on the display of the smartphone

comprising the evaluating unit (K).

The measuring head set (1, 2) according to the invention ensures wireless (Bluetooth) forwarding of the

measured data to the evaluating unit (K), e.g. a smartphone or database which performs more detailed

analysis.

Fig. 2 shows the sensors of measuring heads 1 and 2 from a bottom view, that is, from the direction of the

human body surface. From below, there are ECG electrodes (3, 4) separated from each other and the sensors

(5, 6) detecting the vibrations of the chest, placed in an insulating case made of e.g. a plastic accepted and used

in healthcare devices. The electronic connection between the cable (7) and the measuring heads (1, 2) is

provided by decomposable multipole connectors (13, 14). Electrode 3F serves as the "right leg electrode" of

the classic ECG lead system. The bipolar ECG measured by electrodes 3 and 4 has the following functions:

determining the R-R distances (15) and QRS width (17) indicated in Fig. 6 and based on the above data,

establishing the beginning and end of the QRS wave and defining the QT distance (16).

Fig. 6 explains the parameters mentioned in the scope of ECG measurements and processing. Based on a

uniform international consensus, the waves detected on ECG are called P, Q, R, S, T, and U. Each wave

represents the depolarization (electronic activation) or repolarization (return to the baseline electronic state)

of a specific part of the heart. The QRS complex or ventricular wave shown on the figure, marking the rapid

depolarization of the ventricles, consists of the small negative Q wave which is not always detectable, the

positive R wave, having up to 10 mV amplitude, indicating the stimulation of the main mass of ventricular

muscle, and a negative S wave. The depolarization of the total working ventricular musculature takes place

during the QRS wave; its normal duration is 0.06-0.12 sec: of this, depolarization of the interventricular septum

takes 0.03 sec, and depolarization of the right and left ventricle takes 0.055 sec and 0.068 sec, respectively. The

figure also shows the QT distance which is the total duration of ventricular muscle depolarization and

repolarization combined. QT distance normalized against the heart rate should not be shorter than 0.36 sec

and longer than 0.44 sec in physiologic cases.

During procession, the ECG signal can be used for the distinction between the so-called "majority" and "extra"

beats. In accordance with the idea according to the invention, the moment of the beginning of QRS wave

serves as a reference or anchor for the synchronous averaging of thoracic vibration signals. In case of an

increased QRS length, the QRS parameters (Oravecz et al: Dynamic Analysis of Heart Sounds in Right and Left

Bundle-Branch Blocks, Circulation, 36, 275-283, 1967) promote the distinction between the left and right

ventricular components of the first heart sound (S1) during the summarization of the results.

Fig. 5 shows the block scheme of an exemplary electronic setting of the master and slave 1, 2 measuring heads.

The figure shows a master (1) measuring head and a slave (2) measuring head. Both measuring heads (1, 2)

include an ECG electrode (3, 4) known in itself by the professionals and a sensor (5, 6) capable of taking up

mechanical vibrations which can be implemented with only a microphone or even by a MEMS acceleration

detector. The master (1) measuring head includes the electronic unit processing the signals provided by the

measuring head's (1) ECG electrode (3) and PCG sensor (5). In the presented example, it includes a multi-input

(18) amplifying stage which can be feasible by a bipolar ECG amplifier and e.g. by a type AD8232 circuit known in the field, in accordance with the manufacturer's instructions. The 3F electrode indicates the ground electrode of the input (18) amplifying stage used for bipolar ECG amplifier, and it connects to the appropriate input of the amplifying stage (18). In addition, measuring head 1 includes the amplifying stage (19) connecting with electrode 5 belonging to measuring head 1 which is implemented with a type MCP607 dual operational amplifier in the present example. The output of amplifying stages 18 and 19 is connected with the multiplexer stage (20) and its output is connected with the analog-to-digital converter's (21) input which has a sampling frequency of at least 500 Hz, in this case as well. The analog-to-digital converter (21) in this example is implemented as a type ASDS1248 24-bit circuit and its output is connected in this example with an

Atmega2560 type processor stage (22) which is well-known and working. The processor stage (22) can be more

closely known from several instructions for use in accordance with the all-time needs; on one hand, it connects

with the LCD 8 display through the memory stage (23), and on the other hand it is connected to the Bluetooth

stage (24) allowing and providing wireless communication. In this latter case, it was implemented by a

MicroChipRN42 type commercially available unit. The stored signals are forwarded via Bluetooth connection to

the smartphone used as the evaluating unit (K) for final processing showed in Fig. 7. We also symbolically

presented the part of the body surface (26) where the (9-12) auscultation sites are located.

The ECG electrode (4) belonging to the slave (2) measuring head connects with the measuring head 1, and its

sensor (6) is connected to the input of the amplifying stage (19) already used in measuring head 1. In the

presented example, amplifying stage 19 is identical with amplifying stage 18 used in measuring head 1,

therefore it also consists of a type MCP607 operational amplifier. The output of amplifying stage 19 is

connected to another output of the multiplexer stage (20) in measuring head 1, and this connection is made

possible by the cable (7) connecting the two measuring heads (1, 2) with each other and in addition to

forwarding signals, it also allows electronic energy supply of measuring head 1 in such a way that the battery

(25) placed in measuring head 2 provides not only the supply of measuring head 2 but through one of the

conductors of the cable (7) it also provides energy for measuring head 1 and ensures that its units and stages

are also supplied.

The battery (25) is also selected in accordance with actual needs; and in the case of the presented design, we

used a 3.7 V, 490 mA rechargeable battery.

The display (8) may be for example a 2x16-character LCD display compatible with the Hitachi HD44780 display.

The case of measuring heads 1 and 2 shall be practically made of plastic, in this example it is PVC closed by a

sensor ring on one end. In this sensor ring, there are two built-in ECG DRL circuits which are in connection with

the conductive membrane connected to the sensor ring. A PCG sensor surface is set behind the conductive

membrane which is adjacent to a printed circuit board holding analog elements. The battery (25) is placed on

the other side of the printed circuit board - in the case of measuring head 2 - and on the other side of the

battery (25) is another digital printed circuit board which has a known but here not illustrated electronic

connection with the display (8) embedded into the end-surface of the measuring head case.

In the description of the method according to the invention during the implementation which is only presented

in Fig. 7 as an advantageous example, in step 31, the appropriate auscultation sites (9-12) are selected and the

measuring heads (1 and 2) are placed onto the body surface (26) of the examined person. If the measuring

heads (1, 2) are placed on the auscultation site over the mitral valve (9) and over the aortic valve (10) as shown

in Fig. 4, then the left ventricular signals of the first heart sound (Si) and second heart sound (S2) can be

measured. Similarly, if the measuring heads (1, 2) are placed on the auscultation site over the tricuspid valve

(11) and over the pulmonary valve (12) as shown in Fig. 4, then the right ventricular signals of the first heart

sound (S1) and second heart sound (S2) can be measured. By placing measuring head 1 over auscultation site 9

and measuring head 2 over auscultation site 11, the difference between the S1 heart sound's left and right

ventricular component can be detected. Similarly, by placing measuring head 1 over auscultation site 12 and

measuring head 2 over auscultation site 11, the difference between the S2 heart sound's left and right

ventricular component can be detected. During the application of the invented combined measuring head, the

master measuring head (1) must be placed "above" the mitral valve because then the signal of the slave (2)

measuring head's ECG electrode (4) will go to the phase reverser input of the amplifying stage (18) and the

signal of the mitral valve's ECG electrode (3) will go to the phase holder input and thereby the recorded signal

will be similar to a standard ECG II signal. And during the measurement of the right heart, the measured ECG

becomes similar to the Y component of the vector cardiogram. However, it is important that in both cases, we

receive a sign which is convenient for the determination of the beginning of electronic

activation/depolarization, that is the beginning of QRS interval which is considered as a point of reference in

terms of evaluation and the determination of the end of the T wave, that is the end of repolarization and it can

also be used for the detection of left or right bundle branch block, and by knowing it, the left and right

ventricular components of the S1heart sound can be identified.

In step 32 we perform data collection and its result is presented on the display (8) placed on the master (1)

measuring head, following processing which is to be described in details later. In order to ensure the quality of

data collection, the quality of signals to be recorded are followed on the display (8).

During the processing, in step 33, majority cycles are selected based on the recorded ECG signal, where the

selection of majority cycles takes places by comparing the recorded ECG signals by cycles. Here we examine the

morphological similarity of the ±80 msec environment of the fiduciall", that is, the point with the steepest

gradient by applying correlation coefficients. Of the developing clusters, the most populated cluster is

considered as majority.

In step 34 the following ECG parameters are determined by thresholding procedure: Beginning of P wave,

beginning and end of QRS, end of T wave, and RR distance (the reciprocal of heart rate). During the

interpretation of S1 and S2, QRS width plays a role as it explains the delay of S1 or S2 compared to the

beginning of Q wave.

In step 35, ECG synchronous averaging of the signal segments of the two PCG channels is performed. The data

collection time is adjustable in each combination, but it is advisable to store a record of at least 30 seconds, approximately corresponding to 30 cardiac cycles. During the signal processing, it is expected, even in case of extra beats or noisy segments that there will be at least 25 majority cycles available for the improvement of signal-to-noise ratio by synchronous averaging, which results in an approximately five-fold increase of the root mean square of the signal-to-noise ratio.

In step 36 the border points, that is, the beginnings and ends of the heart sounds and murmurs will be

determined. In case of the averaging of a PCG signal belonging to the n majority cycle, the root mean square of 2 the sum of the partially overlapping signal (J) and noise (Z) signals will tend to zero in a 1/n/ manner, at a

point of the t time axis within the cardiac cycle which does not contain a J(t) heart sound signal yet or already,

only noise Z(t) signal. Accordingly, advancing to the positive direction from the beginning of QRS, the tk value 2 from which the root mean square caused by the averaging does not follow the 1/n/ rule, but stabilizes at a

constant value near the value indicating noiselessness - this tk value is considered as the beginning (or end) of

the heart sound signal. When determining the end of the heart sound signals, we follow the same principle as

above, but to the opposite direction.

In case of both halves of the heart, determination of the beginning of the S1 and S2 heart sounds also form part

of the processing, performed in step 37. The determination of these time points may take place by time

frequency (Fourier) analysis, exploiting the well-known fact that the vibration of the left heart has higher

frequency components than that of the right heart. The obtained results are confirmed by the algorithm

examining the QRS wave parameters of the ECG. According to the article of Oravetz et al in Circulation vol. 36,

275-283, in case of left bundle branch block and right bundle branch block, there is a significant shift in the

beginning of S2 and in the timing of its components, which has a diagnostic significance. The referenced article

includes the deviation of the two types of branch blocks from the normal case. For example in case of heart

failure, the article of N de Oliveira Neto, et al.: "Abnormalities of the Systolic Time Intervals Obtained by

Electronic Stethoscope in Heart Failure" provides data of interest in light of the change of systolic interval

parameters.

In step 38, the processing program summarizes the measurements for the different measuring head placement

combinations, lists the parameters and performs evaluation if needed.

During the method and the application of the measuring arrangement, the following information may be

presented on the device which is connected to the measuring heads (1, 2) of the measuring arrangement - this

may be a smartphone for example - for the professionals interested in the result of the analysis:

- Recording all ECG signals belonging to the registration cycle, which the majority cycle determination is

based upon. This service is only part of the detailed data recording, but it is not included in the short result

provision.

- A segment of the majority ECG cycle in each registration cycle - maximum 4 cycles - lasting from the P

wave on the ECG to the end of the next cycle's R wave, together with the simultaneously registered and

averaged two PCG channels.

- The vertical marker lines drawn above the registered and/or processed signals are visible, the beginning of

P wave determined by the algorithm of the device (smartphone), the beginning and end of QRS wave, and

the end of T wave are marked. The beginning and end of the examined patient's S1 and S2 wave and, if

applicable, the beginning and end of murmurs will be presented on both averaged PCG channels.

- For the sake of diagnostic evaluation, a different color is used for presenting the second marker line

network typical of the healthy population, the left ventricular QS1 and QS2 interval (in medical terms, PEP

and LVET) values, along with their typical band of standard deviation.

The above description shortly introduced the most essential data provision services made possible by the

method according to the invention. An important characteristic of our invention is that the reference

parameters of the S1 and S2 parameters which are the most important in terms of left ventricular function and

which prevail in normal case (based on de Oliveira et al: The Internet Journal of Cardiology, 2007, vol. 5, No. 2),

can be determined and presented on the display of the smartphone by the following regression correlations.

These regression correlations are used for it:

QS1= 65 - 0.3 HR= PEP

The distance of heart sounds in healthy men:

QS2 = 488 - 1.65 HR, S1S2= 428 - 1.35 HR= LVET

The distance of heart sounds in healthy women:

QS2 = 553 - 2.3 HR, S1S2 = 498 - 2.1 HR= LVET

where:

HR: heart rate,

PEP: left ventricular pre-ejection period,

LVET: left ventricular ejection time,

The advantage of our recommended method is that it is suitable for patients of any physique, and can be

matched well with the traditional auscultation practices of the physician. Compared to classic single measuring

head/single sensor scanning, the difference here is that the scanning, performed during the auscultation which

is part of the monitoring process, is carried out using two measuring heads that record the acoustic signals at

two auscultation points as well as the ECG signal which is necessary for interpretation.

Another advantageous implementation mode of the present method allows the built-in processor of the device

to determine the "majority cycles" (thus, extra beats or noisy beats are excluded from the processing) and

derive the noise-reduced end result from their average or median.

A further advantage of the method is that the electromechanical cardiac cycle parameter range of the

examined patient can be compared with the data of a healthy person by literature and thus perform a

preliminary expert interpretation.

According to another advantageous implementation mode of the present method, the results are visually

presented on the display panel of the smartphone (or another computing device), and an optional PCG signal

may also be listened to in parallel upon request (e.g. for educational purposes).

A further advantage of the device is the wireless, e.g. Bluetooth data communication between the measuring

head combination (1, 2) and the evaluating unit (K).

List of referenced symbols:

M measuring unit

K evaluating unit

1 measuring head

2 measuring head

3, 4 electrode

3F electrode

5, 6 sensor

7 cable

8 display

9-12 auscultation site

13, 14 connector

15 R-R distance

16 QT distance

17 QRS width

18 amplifying stage

19 amplifying stage

20 multiplexer stage

21analog-to-digital converter

22 processing stage

23 memory stage

24 Bluetooth stage

25 battery

26 body surface

31-38 step

S1-S4 heart sound

J signal

Z murmur

t time

Claims (8)

1. A method for monitoring specific activity parameters of the human heart comprising

the steps of: arranging measuring heads comprising electrodes of a measuring unit (M) on the chest of a patient;

monitoring predetermined parameters by two measuring heads placed on the chest,

wherein monitoring comprises capturing an electrocardiogram (ECG) signal by ECG electrodes and capturing a phonocardiogram (PCG) signal by PCG electrodes;

transmitting the captured signals wirelessly from the measuring unit to a computing evaluating unit;

evaluating transmitted signals by means of the computing evaluating unit, utilizing the captured ECG signal as a reference time for the PCG monitoring; and

displaying at least one of captured signals and evaluation results with a display

means of the computing evaluating unit; wherein the step of monitoring further comprises:

performing monitoring the ECG and PCG signals simultaneously by two measuring heads, each comprising an ECG electrode and a PCG electrode, and

operating one of the measuring heads as a master measuring head and the other one of the measuring heads as a slave measuring head and controlling operation of the

slave measuring head by the master measuring head; and wherein monitoring is performed in the following order:

capturing ECG and PCG signals between mitral (M) and aortic (Ao) auscultation

points, capturing ECG and PCG signals between tricuspid (T) and pulmonic (AoPu) points,

and determining a time difference between captured left and right ventricular mechanic

contraction by capturing vibrations on the body surface between the Ao and AoPu points, then capturing vibrations on the body surface between the T and M points.

2. The method according to claim 1, wherein quality of the captured signal is displayed

on a display of the master measuring head.

3. The method according to claim 1, wherein for exact determination of the

electromechanical activity's time parameters, the parameters to be determined are derived from parameters of individuals considered healthy by literature standards and their

synchronized, noise-reduced average.

4. The method according to claim 1, wherein a primary evaluation is conducted by

using an expert service built into a smartphone in such a manner that the mechanical cardiac cycle parameters of the measured person are compared to the parameters of

individuals considered healthy by literature standards and their standard deviation.

5. The method according to claim 1, wherein results are visually presented on the

display means of the smartphone and simultaneously the PCG signals are made audible.

6. A measuring arrangement for monitoring specific activity parameters of the human

body, the measuring arrangement comprising: a measuring unit including at least one measuring head comprising an

electrocardiogram (ECG) sensor and at least one measuring head comprising a

phonocardiogram (PCG) sensor; and an evaluating unit having a wireless communication connection with the measuring

unit; wherein the measuring unit comprises two measuring heads designed as master and

slave measuring heads each comprising more than one ECG electrode and PCG electrode, one of the measuring heads is operated as a master measuring head and the other one of

the measuring heads is operated as a slave measuring head, the master measuring head provides control of the slave measuring head for performing simultaneous capturing of the

hearts electromechanical activity; and

wherein the master measuring head comprises a communication stage providing wireless communication with the evaluating unit;

wherein the measuring heads comprise the electrodes for the bipolar ECG measurement in a distributed manner enabling a reference ECG measurement similar to a

Lead II of 12-lead ECG system simultaneously with the left ventricular monitoring and data

collection; wherein the ECG electrode of the master measuring head assigned for the auscultation point of the mitral valve is connected to an inverting input of an amplifying stage; and wherein a ground electrode is arranged on the master measuring head.

7. The measuring arrangement according to claim 6, wherein the measuring heads are

interconnected by a multiconductor cable performing energy and signal transmission.

8. The measuring arrangement according to claim 7, wherein the cable has a length to

allow a physician to carry the measuring arrangement comprising the two measurement heads hung on his/her neck.